INSPIRE Support in GeoServer made easy with HALE
Dear readers,
The GeoSolutions team is working to make the job of publishing Inspire compliant data easier, by enabling the usage of a visual schema mappings editor, HALE, to configure the GeoServer app-schema extension.
Currently, to publish Inspire compliant data in a specific schema (defined through a set of xsd files) using GeoServer, the app-schema extension can be used to map a set of existing data sources (for example shapefiles or PostGIS tables in a database) to given xsd schemas.
The extension allows to:
- create Complex Features, required by many Inspire schemas, while common DataStores only enable the use of Simple Features
- map existing simple features (configured as usual datastores and featuretypes) to elements of a given xsd to produce schema compliant objects
- use Complex Features produced by the extension with standard WFS and WMS protocols
Unfortunately the app-schema extension doesn’t have any graphical user interface or wizard to help with creating the configuration, therefore getting from data to a working set-up can be a tough job.
To solve this problem we looked around and found that a tool to visually map existing data sources to be Inspire compliant already exists, and is the Humboldt Alignment Editor (HALE). This tool allows to:
- import existing source schema(s) and data in various formats (shapefile, databases, xsd / xml)
- import existing target schema(s) (xsd, databases, inspire schemas)
- graphically design transformation mappings from the source to the target
- interactively execute data transformations to verify the result of the mappings
- interactively view data transformation that include geometries on a map
When a set of mappings have been designed and saved (as an Alignment project), the transformations can be applied to existing data via the integrated ETL using the command line, or an ad hoc REST API service.
All of these features make HALE the best candidate to become a configuration UI for the GeoServer app-schema extension, and this is why we are currently working with the HALE community to:
- improve HALE itself adding new kind of transformations needed by our customers
- improve HALE support for data sources, adding spatialite support
- integrate an app-schema configuration generator to automatically create / update app-schema configuration file(s) from an HALE Alignment project
In the process, we hope to improve the app-schema extension itself, fixing bugs where needed, improving performance where possible and probably adding new mapping capabilities to match those available in HALE.
The work is still in progress and some more time is needed to have a working user interface for app-schema, but we are on the way, so stay tuned and get in touch if you’d like to contribute to this effort. As usual, whatever we’ll produce will be released as Open Source.
Last but not least we would like to thanks LaMMa Consortium and the Austrian Meteorological Services (ZAMG) for funding this work under a GeoSolutions Enterprise Services support contract.
